Improvement in bridges



N. PETERS. PHOTO-LITHOGRAFHER. WASHINGTON. Dy CJ fitnited Ctatee Q-aant emitir. f

DAVID'MCOURDY, OF OTTAWA, OHIO.

Letters Patent No. 104,867, dated .Tune 28, 1870; miftedatczl June .17, 1870.

IMPRQVEMENT IN BRIDGES.-

The Schedule referred to in these Letters Patent and making part of the same` full, clear, and exact description thereof, reference be' ing had tothe accompanying drawing andto the letters of reference marked thereon making a part of this specification.

The nature of my' invention consists in the construetionand general arrangement ot' a bridge, as will be hereinafter fully set forth.

In"order to enable others skilled inthe art to which my invention appertains to make and use the same, I will now proceed to describe its construction and operation, referring to the annexed drawing, in which- Figure 1 is a side View, and

Figure 2, a bottom view of my bridge.

A represents the arch or girder of my bridge, formed of planktrussed within itself by boltsava, passing in the direction of' the center of thc circle, and by vertical rods B B. f

-The Yrods B B are, at their lower, ends, provided with clamps b, through which the cords epass, said clamps being tightened by means of nuts (l d, above' and below the clamp on the rod B, said rods being secured on top of the arch Aby means of nuts c c, and each alternate rod is further'. secured by jamnuts f under the arch,

The jam-nuts f f may be used on every rod, if deemed necessary to fully secure the arch; but, in that case, each alternate rod is` tobe a very little shorter, so that, when thc tension yof the cords is brought up, all the springer vibration, and contraction and expansion, will be taken up.`

The arch is tied overhead by means of cross-braces, D D, and may be tied at'the chords below in the same manner,- as Well as by each joist; and to prevent'the arch from twisting, a block, E, of metal or wood, is put in at eachend under the. arch, said block being bolted with thcftimber G below, through the arch f which makes the stops at the abutment, with the shoe H-resting on a metal plat-c or plank, I, free and independent of the abutment endwise, but secured sidewise. v l

The chords G pass through the shoes H, and are secure and tightened by nuts t' t'. t

The joists J J areI placed around the Vertical rods B B,and rest upon the chords C C, or rather upon'- the'clamps bib, through which said chords pass. The floor is laid upon the joists, with suitable railing ifthe arch is Very high, but if not S0 high, then thcarch and rods make the railing.

Having thus fully described my invention,

`\Vhat I claim as new, and desire to secure by Letters Patent., is-

- 1. The arrangement of the arch A, rods B' B,

chords C, bolts aa, clamps l1 b, nuts l (l and e, and jam-nuts j, all substantially as shownl Aand described,v

2.'The blockE and tilnber G, bolted to the arch A, substantially as and for the purposes herein set fort-b.

3. A bridge, when its parts are constructed, arrangedA and combined substantially as herein shown and described. v

4. The combination in a bridge of the two parallel chords O C, notched clamps b b, nuts l l l, an d vertical tic-rods B B, all-substantially as set fort-h.

In testimony that I claim the foregoing, I have" hereunto set my hand this 1st day of Novembcr,`.

DAVID MeCUR-DY.

Witnesses:

J. J. MOORE, C. J. SWAN. 

